The World Wide Web available on the Internet provides a variety of specially formatted documents called web pages. The web pages are traditionally formatted in a language called HTML (HyperText Markup Language). Many web pages include links to other web pages which may reside in the same website or in a different website, and allow users to jump from one page to another simply by clicking on the links. The links use Universal Resource Locators (URLs) to jump to other web pages. URLs are the global addresses of web pages and other resources on the World Wide Web.
Hosted web pages include links that use URLs. However, as web technology evolves, websites have become more and more complex and human error is prone to cause defective web pages that include links that are no longer available. Manual correction of the broken links and other errors on the web pages would take an enormous amount of time.